Forming methods

ABSTRACT

This invention relates to methods for forming polymer(s) including heating of a polymer to be formed to a temperature above its glass transition temperature, continuously depositing (preferably by flowing or laying) the polymer onto a moulding surface (herein the “lower moulding surface”) of a first mould, (preferably in a manner that reduces, eliminates or minimises shear stress or other stress in the polymer so deposited), the polymer remaining above the glass transition temperature, applying a moulding surface (herein the “upper surface”) of the polymer while the polymer remains at a temperature above the glass transition temperature, and allowing the polymer to transition to below the glass transition temperature while within or between the upper and lower moulding surfaces, wherein the polymer is removed from the moulding surfaces. Apparatus is also provided.

Applicant hereby incorporates by reference International ApplicationPCT/NZ2009/000214, filed 7 Oct. 2009, claiming priority from AustralianApplication No. 2008905211 filed 7 Oct. 2008 (also incorporated byreference herein).

FIELD OF THE INVENTION

The present invention relates to forming methods, more particularly,though not solely, to a method of forming or fabricating superfinestructures or nanostructures or both.

BACKGROUND TO THE INVENTION

Mass production forming or fabricating of nanostructures ormicrostructures, such as any manufactured structure having a scalebetween molecular and microscopic, presents challenges to existingforming techniques.

For example, an item or a precursor to an item manufactured in a formingprocess, such as by injection moulding, may have been formed in astressed material state. The forming process itself imparts stressessuch as deformation stress, shear stress, flow stress and temperaturestress to the material or item thus formed. Generally, in existingforming techniques the greater the speed of production the more stresstends to be imparted in to the formed product. Traditionally, thesestresses are increased greatly when attempting to mass produce products.

Further disadvantages of forming products have included the subsequentdeformation of an imprinted or formed item or product surface by theheat remaining in the material following a forming step. The heattransfer rates may impact on the length of time taken for the item orproduct to cool and the imprinted shape to hold its pattern.

It would be beneficial if an item or a precursor material for forming anitem can be manufactured or fabricated in a manner that minimises orreduces the problems associated with formation stresses or stresses thatmay become locked up in the item due to the variations in temperatureacross an item during a forming process. Reducing or minimising overallshrinkages of forming an item to a near net shape also provides formanufacturing efficiencies.

It would therefore be significantly advantageous to be able to massproduce products. Mass production would assist in reducing the effectivecost per unit or cost per unit area produced. Mass production capabilityallows for such efficiencies which previously have not been possible.The ability to mass produce large volumes or large areas enablescommercialisation of products that have previously not been possible bytraditional forming methods.

It is therefore an object of the present invention to provide animproved method for forming or to provide items formed by the method orvia precursors formed by the improved method to provide formed featuresat a nano-scale or a near nano-scale addressing the foregoing problemsor which will at least provide the industry or public with a usefulchoice.

In this specification where reference has been made to patentspecifications, other external documents, or other sources ofinformation, this is generally for the purpose of providing a contextfor discussing the features of the invention. Unless specifically statedotherwise, reference to such external documents is not to be construedas an admission that such documents, or such sources of information, inany jurisdiction, are prior art, or form part of the common generalknowledge in the art.

Further aspects and advantages of the present invention will becomeapparent from the ensuing description which is given by way of exampleonly.

SUMMARY OF THE INVENTION

In a first aspect, the invention broadly consists of a method forforming a polymer comprising: heating of a polymer to be formed to atemperature above its glass transition temperature, continuously flowingthe polymer onto a moulding surface (herein after “lower mouldingsurface”) of a first mould, the polymer remaining above the glasstransition temperature, applying a moulding surface (herein after “uppermoulding surface”) of a second mould to at least the exposed surface(herein after “upper surface”) of the polymer while the polymer remainsat a temperature above the glass transition temperature, and allowingthe polymer to transition to below the glass transition temperaturewhile within or between the upper and lower moulding surfaces, whereinafter the polymer is removed from the moulding surfaces.

In a second aspect, the invention broadly consists of a method forforming a polymer comprising: continuously flowing a polymer that isabove its glass transition temperature, onto a moulding surface (hereinafter “lower moulding surface”) of a first mould, applying a mouldingsurface (herein after “upper moulding surface”) of a second mould to atleast the exposed surface (herein after “upper surface”) of the polymerwhile the polymer remains at a temperature above the glass transitiontemperature, and allowing the polymer to transition to below the glasstransition temperature while within or between the upper and lowermoulding surfaces, wherein after the polymer is removed from themoulding surfaces.

In a third aspect, the invention broadly consists of a method forforming two polymers comprising: heating each of a first polymer and asecond polymer to temperatures above each polymer's respective glasstransition temperature, continuously flowing the first of the polymersonto a moulding surface (herein after “lower moulding surface”) of afirst mould, the first polymer remaining above its glass transitiontemperature, continuously flowing the second of the polymers onto theexposed surface (herein after “upper surface”) of the first polymer, thesecond polymer remaining above its glass transition temperature,applying a moulding surface (herein after “upper moulding surface”) of asecond mould to at least the upper surface of the second polymer whileeach of the polymers remain at a temperature above their respectiveglass transition temperatures, and allowing the polymers to transitionto below their respective glass transition temperatures while heldwithin or between the moulding surfaces, wherein after the polymers,bonded together, are removed from the upper and lower moulding surfaces.

In a fourth aspect, the invention broadly consists of a method forforming a plurality of polymers comprising: heating each of a pluralityof polymers to a temperature above each polymer's respective glasstransition temperature, continuously flowing a first of the polymersonto a moulding surface (herein after “lower moulding surface”) of afirst mould, the first polymer remaining above the glass transitiontemperature, continuously flowing a second of the polymers onto the aexposed surface of the first polymer, the second polymer remaining abovethe glass transition temperature, continuously flowing one or morefurther polymers onto the exposed surface of each further respectivepolymer, each of the further polymers remaining above their respectiveglass transition temperature, applying an moulding surface (herein after“upper moulding surface”) of a second mould to at least the uppersurface of the upper-most polymer while each of the polymers remain at atemperature above their respective glass transition temperatures, andallowing the polymers to transition to below their respective glasstransition temperatures while held within or between the mouldingsurfaces, wherein after the polymers so formed are removed from themoulding surfaces.

In a fifth aspect, the invention broadly consists of a method ofcontinuously forming a polymer comprising: continuously advancing apolymer that is above its glass transition temperature through a formingzone where said polymer is subjected to,

-   -   a. pressure, and    -   b. mould forming to impart a nano-scale sized surface texture        (preferably nano-scale sized texture has at least one dimension        in the range of 0.1-1000 nm) on to at least part of a surface of        said polymer, and    -   c. active heat removal to transition said polymer to below the        glass transition temperature,        wherein after said forming zone the polymer is removed from the        moulding surfaces.

Preferably, wherein said forming zone is defined by a serially advancingmoulding surface or surfaces (herein after “lower moulding surface”) ofa first mould or moulds and a moulding surface or surfaces (herein after“upper moulding surface”) of a second mould or moulds.

Preferably, wherein the whole of the polymer(s) to be formed remainabove their respective glass transition temperatures during at least theinitial applying of a forming pressure onto said polymer(s) between theupper and lower moulding surfaces.

Preferably, wherein the moulding surface(s) are each respectively partof a mould part that is/are thermally conductive.

Preferably, wherein the lower moulding surface and preferably the uppermoulding surface are temperature controllable for maintaining thepolymer(s) to be formed above their respective glass transitiontemperatures at least prior to the step of applying the upper mouldingsurface.

Preferably, wherein the upper and lower moulding surfaces aretemperature controllable for controllably allowing the polymer(s) soformed to reduce to below their respective glass transition temperaturesprior to removing of the polymer(s) so formed from the mouldingsurfaces.

Preferably, wherein the first mould is mounted to a first or lowerplaten.

Preferably, wherein the second mould is mounted to a second or upperplaten.

Preferably, wherein at least one of the moulding surfaces defines one ormore nano or near-nano or micron or near micron sized surface reliefs orprofile.

Preferably, wherein at least one of the moulding surfaces defines a nanoor near-nano or micron or near micron sized surface pattern.

Preferably, wherein applying the upper moulding surface comprisesbringing the upper moulding surface into contact with at least theupper-most surface of the upper polymer.

Preferably, wherein the polymer(s) assume the shape of the lower mouldsurface and upper mould surface when above its polymers glass transitiontemperature.

Preferably, wherein the polymer(s) is/are heated to above the glasstransition temperature and is/are fed via extrusion to an extrusion headfor flowing directly onto the lower moulding surface.

Preferably, wherein a melt pump controls the flow rate of polymer.

Preferably, wherein the polymer(s) when above the glass transitiontemperature is/are in the liquid phase.

Preferably, wherein the moulding surfaces are at temperature(s) justabove the glass transition temperature of the polymer(s) to be formedwhen the polymers are initially located between the upper and lowermoulding surface.

Preferably, wherein the moulding surfaces are maintained at temperaturesabove the glass transition temperature of the polymer(s) during the stepof applying an upper moulding surface to at least the upper surface ofthe polymer or upper-most polymer.

Preferably, wherein at least one of the moulding surfaces comprisesurface reliefs and applying the upper moulding surface, appliespressure to the polymer(s) for moving the polymer(s) into the mouldingsurface(s)'s surface reliefs.

Preferably, wherein the upper moulding surface and lower mouldingsurface apply a moulding pressure to said polymer of up to about 500kg/cm2.

Preferably, wherein the upper moulding surface and lower mouldingsurface apply a moulding pressure to said polymer of up to about 260kg/cm2.

Preferably, wherein the upper moulding surface and lower mouldingsurface apply a moulding pressure to said polymer of up to about 60kg/cm2.

Preferably, wherein the upper moulding surface and lower mouldingsurface apply a moulding pressure to said polymer in the range of about1-200 kg/cm2, 1-150, 1-100, 1-90, 1-80, 1-70, 1-60, 1-50, 1-40, 1-30,1-20, 1-10, 1-9, 1-8, 1-7, 1-6, 1-5, 1-4, 1-3, 1-2, 1-1.5, 1-1.2 kg/cm2.

Preferably, wherein the upper moulding surface and lower mouldingsurface apply a moulding pressure to said polymer of less than about 1kg/cm2.

Preferably, wherein the upper moulding surface and lower mouldingsurface apply a moulding pressure to said polymer of about 0.9, 0.8,0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 kg/cm2.

Preferably, wherein the polymer is a thermosetting or thermoplasticpolymer.

Preferably, wherein the polymer is selected from one of: polycarbonate(PC), polystyrene (PS), general purpose polystyrene (GPPS), polymethylmethacrylate (PMMA), thermoplastic (poly) urethane (TPU), polyethyleneterephthalate (PET), polyester methacrylate (PEM), Polypropylene (PP),High impact polystyrene (HIPS), Acrylonitrile butadiene styrene (ABS),Polyester (PES), Polyamides (PA), Poly(vinyl chloride) (PVC),Polyurethanes (PU), Polyvinylidene chloride (PVDC), Polyethylene (PE),Polytetrafluoroethylene (PTFE), Polyetheretherketone (PEEK)(Polyetherketone), Polyetherimide (PEI) (Ultem), Polylactic acid (PLA),high impact polystyrene, aquilobutalstyrene, nylons, acrylics, amorphouspolymers, polyethylene (PE), polyethylene terephthalate (PET), lowdensity polyethylene (LDPE), low low density polyethylene (LLDPE),thermoplastic ethylene (TPE), polypropylene (PP), rubbers, phenolics andthe like.

Preferably, wherein the upper surface is applied to the polymer(s) toapply pressure to said polymer(s) by virtue of movement of the polymerbetween said two moulding surfaces.

Preferably, wherein said lower moulding surface is supported by aconveyor.

Preferably, wherein said upper moulding surface is supported by aconveyor.

Preferably, wherein said lower moulding surface is supported and movedby a first conveyor and said upper moulding surface is supported andmoved by a second conveyor that is located adjacent said first conveyorin order to position the second moulding surface adjacent said firstmoulding surface and move said first and second moulding surfacesthrough a pressure zone at where the polymer is subjected to pressurebetween said first and second moulding surfaces.

Preferably, wherein said polymer is above its glass transitiontemperature upon entering said pressure zone.

Preferably, wherein the temperature of at least one of said first andsecond moulding surfaces is actively controlled in said pressure zone.

Preferably, wherein the temperature of the lower moulding surface isactively controlled prior to the pressure zone.

Preferably, wherein the temperature of the lower moulding surface issufficiently high to help keep the polymer deposited thereon, and priorto said polymer entering said pressure zone, above its glass transitiontemperature.

Preferably, wherein actively controlled heat removal occurs from saidpolymer via at least one of said upper and lower moulding surfaces, whensaid polymer is in said pressure zone, to transition said polymer fromabove its glass transition temperature to below its glass transitiontemperature within said pressure zone, at least by the virtue of thecontrol of temperature of at least one of the first and second mouldingsurfaces.

In a further aspect, the invention broadly consists of a method ofcontinuously forming a polymer comprising: laying a sheet of a polymerthat is below its glass transition temperature onto a moulding surface(herein after “lower moulding surface”) of a first mould, transitioningthe polymer to above its glass transition temperature, advancing saidpolymer into a pressure zone whilst supported by said lower mouldingsurface and whilst remaining above its glass transition temperature,said pressure zone defined by said lower moulding surface and a mouldingsurface (herein after “upper moulding surface”) of a second mouldpositioned relative said upper moulding surface to contact at least theexposed surface (herein after “upper surface”) of the polymer while thepolymer remains at a temperature above the glass transition temperatureand to apply pressure to said polymer between said upper and lowermoulding surfaces, and controlling the removal of heat from said polymerwhilst in said pressure zone to transition said polymer to below theglass transition temperature, wherein after the polymer is removed fromthe moulding surfaces.

Preferably, wherein the method is for mass production formed polymer.

Preferably, claims wherein the method is for continuously forming apolymer.

Preferably, wherein the method is used to form nano-scale sized texture(preferably the nano-scale texture has at least one dimension in therange of 0.1 to 1000 nm) onto at least one of the surfaces of saidpolymer.

Preferably, wherein at least one of the upper and lower mouldingsurfaces includes as nano-scale sized surface texture (preferably thenano-scale texture has at least one dimension in the range of 0.1 to1000 nm) that is to impart a substantially corresponding nano-scalesized surface texture (preferably the nano-scale texture has at leastone dimension in the range of 0.1 to 1000 nm) onto said polymer formedby said method.

In a further aspect, the invention broadly consists of a polymer film orsheet that is formed by the method as claimed in anyone or more of thepreceding claims.

In a further aspect, the invention broadly consists of a polymer film orsheet as defined above that includes a nano scale sized surface texture(preferably the nano-scale texture has at least one dimension in therange of 0.1 to 1000 nm) on at least one of its surfaces.

In a further aspect, the invention broadly consists of a non-reflectiveproduct formed according to the process as defined in the above aspects.

In a further aspect, the invention broadly consists of an apparatus forcontinuously forming a polymer (preferably to define a nano-scale sizedsurface texture onto at least part of the surface of said polymer soformed) comprising: an extruder, including an extruder head, forcontinuously extruding (preferably liquid) polymer extrudate, a formingzone to receive said extrudate above its glass transition temperature,said forming zone defined by a serially advancing moulding surface orsurfaces (herein after “first moulding surface”) of a first mould ormoulds and a serially advancing moulding surface or surfaces (hereinafter “second moulding surface”) of a second mould or moulds, said firstmoulding surface(s) preferably presented to receive (preferably bylaying down onto it) said polymer extrudate prior to it advancing intosaid forming zone and to carry said polymer extrudate into said formingzone, said forming zone configured to subject said polymer extrudate to,

-   -   a. pressure, and    -   b. mould forming (to preferably impart a nano-scale sized        surface texture onto at least part of a surface of said        polymer), and    -   c. active heat removal to transition said polymer to below the        glass transition temperature.

Preferably, wherein said active heat removal occurs via at least one ofsaid first and second moulding surfaces by at least one temperaturecontrolled heat sink.

Preferably, wherein a plurality of heat sinks are provided for at leastone of said first and second moulding surfaces, said heat sinks spacedrelative to each other in a forming zone advanced and retarded moreorientation.

Preferably, wherein a said heat sink advanced more is of a temperaturelower than an adjacent retarded more heat sink, in order toprogressively reduce the temperature of said polymer as it advancesthrough said forming zone.

Preferably, wherein a temperature controller is provided for each saidheat sink to control the temperature of each heat sink.

Preferably, wherein at least one of said first and second mouldingsurfaces can transfer heat to said polymer at least at the beginning ofsaid forming zone, by virtue of a heater.

Preferably, wherein said first moulding surface is presented to receivesaid polymer prior to said polymer entering said forming zone.

Preferably, wherein a heater is provided to heat said first mouldingsurface prior to said first moulding surface entering said forming zone.

Preferably, wherein at least one heater is provided to heat at least oneof said first and second moulding surfaces prior their entering saidforming zone.

Preferably, wherein said heater(s) can facilitate the keeping of thepolymer above its glass transition temperature at at least the beginningof the forming zone.

Preferably, wherein said heater(s) can facilitate the keeping of thepolymer above its glass transition temperature at least just prior tothe polymer entering the forming zone.

Preferably, wherein at least one of said first and second mouldingsurfaces include a nano-sized surface texture that can form asubstantially corresponding nano-sized surface texture of said polymer.

Preferably, wherein said there are a plurality of discreet and/orsequentially advanced first and second moulding surfaces provided foradvancement through said forming zone, each advancing through saidforming zone in a paired relationship at a synchronised speed.

Preferably, wherein a finite or discreet number of first and secondmoulding surfaces are provided that repeatedly pass through said formingzone.

Preferably, wherein a finite or discreet number of first and secondmoulding surfaces are provided that pass through said forming zone onlyonce.

Preferably, wherein at least one of said first and second formingsurface is/are each of a continuous in form.

In a further aspect, the invention broadly consists of an apparatus forcontinuously forming a polymer (preferably to define a nano-scale sizedsurface texture onto at least part of the surface of said polymer soformed) comprising: a forming zone to receive a polymer at a temperaturewhere the polymer is above its glass transition temperature, saidforming zone defined by a serially advancing moulding surface orsurfaces (herein after “lower moulding surface”) of a first mould ormoulds and a serially advancing moulding surface or surfaces (hereinafter “upper moulding surface”) of a second mould or moulds, said lowermoulding surface(s) preferably presented to receive said polymer priorto it advancing into said forming zone and to carry said polymer intosaid forming zone, said forming zone configured to subject said polymerto,

-   -   a. pressure, and    -   b. mould forming (to preferably impart a nano-scale sized        surface texture onto at least part of a surface of said        polymer), and    -   c. active heat removal to transition said polymer to below the        glass transition temperature.

In a further aspect, the invention broadly consists of an apparatus forcontinuously forming a co-extruded material (preferably to define anano-scale sized surface texture onto at least part of the surface ofsaid material so formed) comprising: at least one extruder for formingan extrudate of at least two polymers in a co-extruded form, a formingzone to receive said extrudate in a condition where at least one andpreferably both/all polymers are above their respective glass transitiontemperature, said forming zone defined by a serially advancing mouldingsurface or surfaces (herein after “first moulding surface”) of a firstmould or moulds and a serially advancing moulding surface or surfaces(herein after “second moulding surface”) of a second mould or moulds,said first moulding surface(s) preferably presented to receive(preferably by laying down onto it) said extrudate prior to it advancinginto said forming zone and to carry said extrudate into said formingzone, said forming zone configured to subject said polymer extrudate to,

-   a. pressure, and-   b. mould forming (to preferably impart a nano-scale sized surface    texture onto at least part of a surface of said extrudate), and-   c. active heat removal to transition said extrudate to below the    glass transition temperature.

Preferably, wherein a said extruder is provided for each of saidpolymers.

In a further aspect, the invention broadly consists of a polymer with anano-sized surface texture formed by the above apparatus.

In a further aspect, the invention broadly consists of a continuouslyformed polymer with a nano-sized surface texture.

In a further aspect, the invention broadly consists of a continuouslyformed coextruded material comprising at least two polymers wherein atleast one polymer includes a nano-sized surface texture.

In a further aspect, the invention broadly consists of continuouslyforming a polymer with a nano-sized surface texture.

In a further aspect, the invention broadly consists of continuouslyforming a coextruded material comprising of at least two polymers,wherein at least one of said polymers includes a nano-sized surfacetexture.

In a further aspect, the invention broadly consists of a sheet or filmof at least one polymer (and preferably at least two co-extrudedpolymers) that includes a nano-sized surface texture that has beenformed by continuous or non-discrete or non finite processing of atleast one precursor polymer material.

In a further aspect, the invention broadly consists of a single sheet orfilm of at least one polymer (and preferably at least two co-extrudedpolymers) that includes plurality of identical and repeated zones ofnano-sized surface texture that has been formed by a continuous ornon-discrete or non finite process.

In a further aspect, the invention broadly consists of a plurality ofdiscreet sheets or film of at least one polymer (and preferably at leasttwo co-extruded polymers) that each include identical nano-sized surfacetexture that has been separated from a single sheet or film precursorformed in a continuous or non discrete or non finite manner.

Preferably, the lower moulding surface is mounted to a first or lowerplaten. Preferably, the upper moulding surface is mounted to a second orupper platen. Preferably, the moulding surface is comprised of one ormore nano or near-nano or micron or near-micron sized surface reliefs orprofile.

Preferably, applying the upper moulding surface comprises bringing theupper moulding surface into contact with at least the upper-most surfaceof the upper polymer.

Preferably, wherein the polymer(s) assume the shape of the lower mouldand upper mould when above each polymers glass transition temperature.

Preferably, the polymer(s) heated to above the glass transitiontemperature is fed via extrusion to an extrusion head for flowing intothe lower moulding surface. More preferably, a melt pump controls theflow rate of polymer to the extrusion head.

Preferably, the polymer(s) is in the liquid phase.

Preferably, the moulding surfaces are provided at temperaturessubstantially at or near or above the glass transition temperature ofthe polymer(s) to be formed. More preferably, the moulding surfaces aremaintained at temperatures substantially at or near or above the glasstransition temperature of the polymer(s) during the step of applying anupper moulding surface to at least the upper surface of the upper-mostpolymer. Most preferably, the moulding surfaces are controllable to beat temperatures at least above the glass transition temperature of thepolymer(s) to be formed.

Preferably, the moulding (die) surface(s) are thermally conductive. Morepreferably, the moulding (die) surface(s) having relatively higherthermal conductivity than other moulding (die) surfaces may be used.Preferably, the moulding surface is one or more of: nickel, steel,aluminium, carbon. Preferably, the moulding (die) surface(s) arethree-dimensional moulding surfaces (i.e. not planar).

Preferably, a near net shaped is formed on flowing of the polymermaterial to the lower moulding surface. Preferably, a net shape isformed on applying of the upper moulding surface to at least the uppersurface of the upper-most polymer.

Preferably, applying the upper moulding surface applies pressure to thepolymer(s) for moving the polymer(s) into the die surface. Morepreferably, applying the upper moulding surface assists in removing ofair from the moulding surface, allowing the polymer(s) to flow into themoulding surface(s).

Preferably, pressure is applied while the materials or polymer(s) to beformed remain above their glass transition temperatures.

Preferably, the upper moulding surface applies a moulding pressure of upto about 500 kg/cm², optionally up to about 260 kg/cm², optionally up toabout 60 kg/cm², optionally the pressure is in the range of about 1-200kg/cm², 1-150, 1-100, 1-90, 1-80, 1-70, 1-60, 1-50, 1-40, 1-30, 1-20,1-10, 1-9, 1-8, 1-7, 1-6, 1-5, 1-4, 1-3, 1-2, 1-1.5, 1-1.2 kg/cm².Alternatively, the pressure applied may be less than about 1 kg/cm²,optionally about 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 kg/cm².

Preferably, cooling and/or skinning of the polymer(s) are allowed tobegin occurring after the polymer(s) has taken the shape of the mouldingsurface(s). For example, cooling and/or skinning are allowed to beginoccurring after the step of applying the upper moulding surface and theupper moulding surface has exerted a moulding pressure.

In a further aspect, the present invention broadly consists in a methodof forming an item in a manner to include a surface or surfaces withsurface detail at a nano or near nano-scale, said method comprising:applying by flowing or laying or depositing a formable material onto asurface, and forming the material.

In another aspect, the present invention broadly consists in a method offorming an item with at least one surface that includes nano-sizedsurface relief, said method comprising: introducing onto a surface of afirst platen a layer or layers of precursor material(s) to be formed,said material being in a molten or optionally a near molten or at leasta non-rigid state when introduced, applying a pressure onto the layer(s)by way of a second platen that is displaced towards said first platen,to at least in part form the precursor material, wherein one or bothplaten carry or have a surface that includes nano-sized surface reliefto form the material with, at least in part, a negative thereof.

Preferably the method comprises applying the material when the materialis in a relaxed or a reduced stress condition.

Preferably, the material may be a flowable material. Even morepreferably the material may be at or near a substantially molten orsemi-molten state. Most preferably, the material may be in its liquidphase.

Preferably applying the material to the surface may be by flowing thematerial.

Preferably the material may be applied to the surface to a depth of lessthan about 50, 40, 30, 20, 10 mm, more preferably less than about 5 mm,even more preferably less than about 3 mm, most preferably less thanabout 2 mm. Yet more preferably the material may be applied to thesurface to a depth of about 0.1 mm to about 3 mm. Alternatively, thedepth is about 4, or 3, or 2 or 1 mm.

Alternatively, the depth of material applied to the surface may be to adepth of at least about 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25,30, 35 40, 45, 50 or 55 micrometers or about 56, 60, 65, 70, 75, 80, 85,90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160,165, 170, 175, 180, 185, 190, 195, 200, 220, 240, 260, 280, 290, 300,350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000,1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600,1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2050, 2100, 2150, 2200,2250, 2300, 2350, 2400, 2450, 2500, 2550, 2600, 2650, 2700, 2750, 2800,2850, 2900, 2950, 3000, 3500, 3550, 3600, 3650, 3700, 3750, 3800, 3850,3900, 4000, 4050, 4100, 4150, 4200, 4250, 4300, 4350, 4400, 4450, 4500,4550, 4600, 4650, 4700, 4750, 4800, 4850, 4900, 4950, 5000 micrometersor 0.1 millimeters to about 3 millimeters and useful ranges may beselected between any of these values (for example, about 0.5 millimetersto about 3 millimeters, about 0.2 millimeters to about 2 millimeters).

Preferably the material may be applied to the surface to a depth suchthat reheating of the imprinted surface of the material or product onceremoved from the die is minimised.

Preferably the thinner the depth of material applied to the surface thefaster the forming (compression or imprinting) process needs to be totake place and the item or product thus formed will have a shortercooling time.

Preferably the material for forming is applied to a substrate which isthen placed on the surface or platen for forming. The substrate may beany depth. The depth of material applied may also be to any depth, themethod of forming imprinting a nano-scale impression or pattern onto thematerial

Preferably where the material is polystyrene its temperature may becontrolled to be about 230° C. on contact with the surface.

Preferably where the material is polycarbonate its temperature may becontrolled to be about 300° C. on contact with the surface.

Preferably the material may be temperature controlled according topredetermined material rheological characteristics. For example, such asreaching a molten or a semi-molten state or a liquid phase that allowsfor flowing of the material to the surface.

Preferably the material may be temperature controlled and allowed topool before applying the pooled material to the surface by flowing. Inan alternative, the material may be provided to the surface insubstantially a sheet formation. For example, the material can be anextrudate (i.e. continuous body of flow) from an extrusion system,optionally including a melt pump.

Preferably the material may be one or more of: a material able to beheated to above its glass transition temperature and continuously flowedin a controlled manner on to a moulding surface (the material being inthe liquid phase), a molten mouldable material, a thermoformablematerial applied at a thermo-formable temperature, a thermoformablematerial to be heated by the surface or a forming tool or tools to aformable condition, a thermoformable material or molten mouldablematerial to be cooled by the surface or a forming tool or tools orotherwise, a thermoformable material to be thermoset by the surface or aforming tool or tools, and any of the foregoing together with one ormore material of a different character. In one embodiment, material canbe flowed onto the die surface at near molten state, heated while on thedie surface to raise the material above its glass transition temperaturethereby allowing the material to assume the shape of the mould when inits liquid phase.

Preferably the material may be selected from a thermosetting polymer ora thermoplastic polymer.

Preferably the material may be applied to the surface at athermoformable temperature.

Preferably the material may be a polymeric composite.

Preferably the material may be a polycarbonate (PC) or a polystyrene(PS) or a general purpose polystyrene (GPPS) or a polymethylmethacrylate (PMMA), thermoplastic polyurethanes (TPU), polyethyleneterephthalate (PET), polyester methacrylate (PEM), Polypropylene (PP),High impact polystyrene (HIPS), Acrylonitrile butadiene styrene (ABS),Polyester (PES), Polyamides (PA), Poly(vinyl chloride) (PVC),Polyurethanes (PU), Polyvinylidene chloride (PVDC), Polyethylene (PE),Polytetrafluoroethylene (PTFE), Polyetheretherketone (PEEK)(Polyetherketone), Polyetherimide (PEI) (Ultem), Polylactic acid (PLA).

Further example materials that may be used with the method of forming ofthe present invention are as follows. Various thermal formable materialsmay be used such as but not limited to polystyrene (PS), high impactpolystyrene, polycarbonate (PC), aquilobutalstyrene (ABS), nylon, andall acrylics and not just those limited to crystalline polymers. Variousthinner plastic materials may be used such as amorphous polymers but notlimited to amorphous polymers and may be for example polyethylene (PE),polyethylene terephthalate (PET), low density polyethylene (LDPE), lowlow density polyethylene (LLDPE), thermo-plastic urethane (TPU),thermoplastic ethylene (IPE) and polypropylene (PP). For example theremay be a polypropylene from 1 to 20 layers fed into the machine and withthe appropriate dies in place there may, for example be of the form of,plates and bowls or similar dished or shaped materials formed. Further,thermoset materials may be used such as rubbers, phenolics and the like.

Preferably the material may be an optical media, such as any one or moreof the following: ultraviolet stabilised thermoplastic polyurethane(TPU), polycarbonate (PC), polymethyl methacrylate (PMMA), generalpurpose polystyrene (PS). Optical media may for example be materialssuitable as optical lenses.

Preferably there may be a number of varying materials able to be fed forflowing and use in the method of forming according to the presentinvention. For example, further suitable materials may comprise thoseable to be affected or acted upon by the pressure of a formingoperation, for example in a forming zone. Such action may be catalysed,created, or formed by the action of pressure and or heat but the endresult is that at least that one material of the materials for forminghas a formed change imparted to it. In a further example, a ductilematerial such as a sheet metal may be feed in with various materialsabove and below it and the metallic material or malleable material isthus formed into the desired shape in the pressure forming zone andregardless whether the other materials are affected by the pressureforming zone provided that at least that one material, in this instance,may be at a molten or semi-molten condition, for example a semi-moltensheet metal.

The basic breakdown of materials that may be formed are those that willretain shape or take on a shape or imprint under pressure alone (forexample malleable or ductile metals such as lead, copper, zinc or thelike, plastics or the like) thermoplastic compounds that require heat toenable them to be formed, thermosetting compounds that require heat orsome other form of catalyst in addition with pressure can be formed, orin general thermoformable compounds that require heat and pressure toallow formation thereof. As an example a rubber can be pressure formedbut also with the addition of heat may facilitate further cross linkingof the rubber molecules so that one the pressure and heat are removedthe shape imparted to the rubber material is retained.

In other materials it may be the pressure which forms the material andthe heat which sets the material off for example in thermosettingmaterials or two pot or more materials which require heat as a catalyst.For example a feed material of preimpregnated carbon fibre could be onesuch material the application of pressure forming the material and theapplication of heat setting the material off and curing the matrix or anepoxy.

Preferred materials are those capable of being heated such that thematerial or constituents of the material can be put into the liquidphase (i.e. above the material's glass transition temperature, T_(g)).On cooling (i.e. reducing to below the material's glass transitiontemperature, T_(g)), the material is allowed to solidify (crystallise)and thereby retain the shape or surface relief pattern of a mould intowhich the material was flowed when in the liquid phase.

Preferably the material may form a part of or be a conductive polymer.

Preferably the material may form a part of or be a polymer wounddressing.

Preferably, the product formed may be subjected to a metalizingtreatment. More preferably, a formed product subjected to a metalizingtreatment may have the formed material (polymer(s)) removed, for exampleby dissolution, the resulting metal structure having a negative detailof the formed product's surface.

Preferably, the product so formed may be of an anti-reflective orstrongly non-reflective surface relief structure.

Preferably the surface is presented to or forms a part of a formingzone. Preferably the forming zone is a pressure forming zone.

Preferably the surface may form a part of a surface of a forming block.Preferably the surface may be one surface of a forming tool or a die oran imprinter. Preferably the surface is one platen of a press or aforming tool.

Preferably the surface is a part of a continuous forming tool (CFT).Preferably the surface is a part of a moving belt former (MBF).

Preferably forming may include imprinting. Preferably the die may be animprinter die.

Preferably the forming tool or die or imprinting surface for forming thematerial comprises one or more metal coated nanotubes. More preferably,the metal coated nanotubes are arranged or configured according to apredetermined product to be formed. Most preferably, the mouldingsurface is a nickel die surface.

Preferably surface is one platen of a press with an opposing platen ofsuitable topology for imprinting or pressing a desired pattern into thematerial.

Preferably the topology is a profile. Preferably one or both of theplaten include or carry a surface defining nano-scale surface detail tobe formed onto the material

Preferably the material may be temperature controlled before applying tothe surface. Preferably the material may be temperature controlled whenapplied to the surface.

Preferably the material may be temperature controlled before applying tothe surface and temperature controlled when applied to the surface.

In yet another aspect, the present invention broadly consists in amethod according to any one of the aspects above to form one or more ofthe following types of items: membranes for separation such as forseparation of components from or within water, chemicals, gases, blood,or use within fuel cells, sensor devices, light diffusers, lightemitters, wave reflecting or absorbing such as radar etc, electroniccircuits or circuitry, particle alignment or aligning technologies,water repellents or water repelling technologies such as hydrophobicmaterials, optical media such as a liquid crystal display (“LCD”) or acompact disc (“CD”) or a digital video disc (“DVD”) technology or aphoto-voltaic cell, memory storage devices, medical devices such as forskin repair or wound repair (e.g. bandages), drug delivery mechanisms ordevices, reduced (low) friction surface materials, increased (high)friction surface materials, lamination technology, radio frequencyidentification (“RFID”) chips, conductive polymer layers/ products/circuits, light bending technologies such as negative light reflections,anti-reflective surfaces or formed surface structures which aresubsequently metallised and the formed product material removedtherefrom.

In yet another aspect, the present invention broadly consists in one ormore of the following items formed from a material precursor that islaid or applied onto one platen of a press to be formed in conjunctionwith at least one other platen pressed toward one another, wherein theitems may be: membranes for separation such as for separation ofcomponents from or within water, chemicals, gases, blood, or use withinfuel cells, sensor devices, light diffusers, light emitters, wavereflecting or absorbing such as radar etc, electronic circuits orcircuitry, particle alignment or aligning technologies, water repellentsor water repelling technologies such as hydrophobic materials, opticalmedia such as a liquid crystal display (“LCD”) or a compact disc (“CD”)or a digital video disc (“DVD”) technology or a photo-voltaic cell,memory storage devices, medical devices such as for skin repair (e.g.bandages), drug delivery mechanisms or devices, reduced (low) frictionsurface materials, increased (high) friction surface materials,lamination technology, radio frequency identification (“RFID”) chips,conductive polymer layers/ products/ circuits, light bendingtechnologies such as negative light reflections, anti-reflectivesurfaces or formed surface structures which are subsequently metallisedand the formed product material removed therefrom.

Preferably the item formed may be an optical media includes one or moreof a photovoltaic cell, a compact disc (CD), a digital video disc (DVD).Preferably the item formed may be an optical media includes a liquidcrystal display (“LCD”). Preferably the item formed may be an element ofa conductive circuit.

Preferably one or both of the platen include or carry a surface definingmicron-scale or nano-scale surface detail to be formed onto the materialprecursor.

Incorporated by reference herein is PCT/NZ2006/000301 that describes animproved method of forming to which the present invention may haveapplication. Also incorporated by reference herein is PCT/NZ2006/000300that describes an improved forming apparatus to which the presentinvention may have application.

Definitions

“Nanoscale” or “nano” as used herein has the following meaning—havingone or more dimensions in the range of 0.1 to 1000 nanometers.

“Liquid phase” is a phase of the material other than solid or gaseous.That is, a phase of the material being a liquid. Liquid phase is one ofthe three basic structural states of matter in which the thermalmobility of molecules or atoms is comparable with the cohesiveness,having them connected but fluid in a mass.

“Molten” as used herein has the following meaning—having materialphysical properties whereby increased internal energy of the material,typically by the application of heat, for example to a minimum specifictemperature such as the melting point, changes the physical propertiesor state of the material from a solid to the liquid phase.

“Semi-molten” as used herein has the following meaning—a material havingphysical properties or state between that of a solid phase and those ofa “molten” state or a “liquid phase”.

The term “comprising” as used in this specification means “consisting atleast in part of”. When interpreting each statement in thisspecification that includes the term “comprising”, features other thanthat or those prefaced by the term may also be present. Related termssuch as “comprise” and “comprises” are to be interpreted in the samemanner.

This invention may also be said broadly to consist in the parts,elements and features referred to or indicated in the specification ofthe application, individually or collectively, and any or allcombinations of any two or more said parts, elements or features, andwhere specific integers are mentioned herein which have knownequivalents in the art to which this invention relates, such knownequivalents are deemed to be incorporated herein as if individually setforth.

The invention consists in the foregoing and also envisages constructionsof which the following gives examples only.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the accompanying drawings preferred embodiments of thepresent invention are now described, whereby:

FIG. 1 is a nano-size scanning electron microscope image illustratingpolymer flow when in a liquid state formed according to the presentinvention,

FIG. 2 is an atomic force microscope measurement of the productillustrated by FIG. 1,

FIG. 3 is an atomic force microscope image of a part of the productillustrated by FIG. 1,

FIG. 4 is a nano/micron size (DVD) scanning electron microscope image ofa nano-scale product formed according to the present invention, and

FIG. 5 is an atomic force microscope measurement of the productillustrated by FIG. 4,

FIG. 6 is a graphical representation of temperature of the material tobe formed across stages of the forming process according to the presentinvention,

FIG. 7 is a side view of an extrusion head with a single extrudateflowing onto a lower moulding surface,

FIG. 8 is a perspective view of the embodiment of FIG. 7,

FIG. 9 illustrates an embodiment of FIGS. 7 and 8 with an upper mouldingsurface configuration in-situ,

FIG. 10 is a perspective view of the embodiment of FIG. 9,

FIG. 11 is a perspective view similar to that of FIG. 8 but with asingle extrusion head flowing two extrudate onto a lower mouldingsurface,

FIG. 12 is an alternative embodiment to the configuration of FIG. 11 inwhich two extrudate are flowed onto a lower moulding surface from a pairof extruder heads and in which an upper moulding surface is shownin-situ for application of multiple material layers according to theinvention,

FIGS. 13 a, 14 a, 15 a are SEM images of the moulding surfaces used togenerate the formed pattern products shown in corresponding respectiveFIGS. 13 b, 14 b, 15 b,

FIG. 16 is a schematic configuration of a particular moulding surface,

FIGS. 17-21 are SEM images of polymer flowed onto the moulding surface fFIG. 16 and products thus formed according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be describedwith reference to the figures.

This invention recognises significant advantages in providing a methodof forming a formable material when the material is provided in aflowable form or condition or state for a forming operation. Productprocessing line speeds can be greatly increased without loss of formedproduct quality. Further, this invention contemplates the forming ofproducts of high quality reproducibility and high definition.

It is anticipated a limiting factor for maximum processing speed of thisinvention is the ability to, with some degree of accuracy, control therate of feed and flow of material to be formed to the moulding surface.It will be appreciated that the improvement in flow rate control ofextrudate will further enable greater processing speeds in due course.

In a first embodiment of the invention there is provided a method forforming a polymer comprising heating of a polymer to be formed to atemperature above the glass transition temperature (T_(g)), continuouslyflowing the polymer P(a) onto a lower moulding surface 2, the polymerP(a) remaining above the glass transition temperature, applying an uppermoulding surface 3 to at least the upper surface 3 a of the polymer P(a)while the polymer P(a) remains at a temperature above the glasstransition temperature, and allowing the polymer P(a) to reduce to belowthe glass transition temperature while held within or between themoulding surfaces 2, 3. The polymer P(a) so formed in this manner isthen removed from the moulding surfaces 2, 3.

In a second embodiment of the invention there is provided a method forforming two polymers comprising heating each of a first polymer P(a) anda second polymer P(b) to a temperature above each polymer's respectiveglass transition temperature (T_(g)), continuously flowing the first ofthe polymers P(a) onto a lower moulding surface 2, the first polymerP(a) remaining above the glass transition temperature, continuouslyflowing the second of the polymers P(b) onto the upper surface 3 a ofthe first polymer P(a), the second polymer P(b) remaining above theglass transition temperature, applying an upper moulding surface 3 to atleast the upper surface 3 b of the second polymer while each of thepolymers P(a), P(b) remain at temperatures above their respective glasstransition temperatures, and allowing the polymers P(a), P(b) to reduceto below their respective glass transition temperatures while heldwithin or between the moulding surfaces 2, 3. The polymers P(a), P(b) soformed in this manner are then removed from the moulding surfaces.

In a third embodiment of the invention there is provided a method forforming a plurality of polymers comprising heating each of a pluralityof polymers to a temperature above each polymer's respective glasstransition temperature, continuously flowing a first of the polymersP(a) onto a lower moulding surface 2, the first polymer P(b) remainingabove the glass transition temperature (T_(g)), continuously flowing asecond of the polymers P(b) onto the upper surface 3 a of the firstpolymer P(a), the second polymer P(b) remaining above the glasstransition temperature, continuously flowing one or more furtherpolymers onto the upper surface 3 x (not shown) of each furtherrespective polymer P(x) (not shown), each of the further polymersremaining above their respective glass transition temperature, applyingan upper moulding surface 3 to at least the upper surface 3 x of theupper-most polymer P(x) while each of the polymers remain at atemperature above their respective glass transition temperatures, andallowing the polymers to reduce to below their respective glasstransition temperatures while held within or between the mouldingsurfaces 2, 3. In his manner the polymers P(a), P(b), P(x) so formed areremoved from the moulding surfaces 2, 3.

Advantageously, the pressure applied from the upper moulding surface isapplied while the materials or polymer(s) to be formed remain abovetheir glass transition temperatures.

Cooling and/or skinning of the polymer(s) is allowed to begin occurringafter the polymer(s) has taken the shape of the moulding surface(s) 2,3. For example, cooling and/or skinning are allowed to begin occurringafter the step of applying the upper moulding surface and the uppermoulding surface has exerted a moulding pressure.

FIGS. 7-12 generally illustrate the continuous flow of polymer P(a),P(b) ((P(x) not shown) from an extrusion head 6 onto a lower mouldingsurface 2 of a continuous forming tool (CFT) or moving belt former (MBF)or other endless belt system 1. For ease of illustration, the uppermoulding surface 3 is not shown in contact with the upper-most surfaceof the polymers P(a), P(b), P(x). However, it will be appreciated theupper moulding surface 3 can be controlled in height or gauging abovethe lower moulding surface 2 and lowered to a position such that theupper moulding surface 3 is applied to at least the upper-most surfaceof the polymers being moulded. Alternatively, the lower moulding surfacemay be brought towards the upper moulding surface. Adjustment of thedistance between the upper and lower moulding surfaces may be adjustedduring the forming process.

The extrusion head 6 can be that as used with any extrusion system whichis capable of controlling the flow of material (polymer) to be mouldedto the lower moulding surface 2. In addition to an extruder, a melt pump(not shown) may optionally be used in-line with the extruder to assistor improve accuracy and control of flow of extrudate to the mouldingsurface 2. A melt pump may be a particularly useful addition forincreasing extruder output of polymer and controlling polymer extrudateflow rate.

With reference to the figures, an embodiment of the present inventionshall now be discussed. As shown by the FIG. 6, temperature profile of amaterial is to be varied during the processing of the material accordingto the invention. The temperature of a material to be processed isindicated by T_(P). For ease of reference, the process has also beendivided into segments, although it will be appreciated that improvedcontrol systems and sensing during the process may allow for the processto be divided into a greater number of controllable segments. Thesegments shown are for general illustration. The process of theinvention shall now be described in further detail.

Materials to be processed for forming are chosen. That material ormaterials are elevated to a temperature above each material's glasstransition temperature (T_(g)). This initial heating stage is referredto as first temperature zone 1 (TZ-1). This step allows for putting thematerial(s) to be formed into a “flowable” state. Such a state is neededto allow the material to be controllably flowed onto a lower surfacemould 2 on a CFT or MBF or endless belt system 1—the second temperaturezone (TZ-2). It should be appreciated other forms of providing amoulding surface for continuous flowing of a material to be formed ispossible.

During the second temperature zone (TZ-2) the material or environment inwhich the material is present (i.e. surrounding air or die or mouldingsurface(s)) is controlled to allow the material(s) to remain above theirT_(g), for example a heater or heaters may be used. The upper die ormoulding surface 3 is then applied to the material(s) to be formed. Inthis manner, at least the surfaces of the material in contact with thedie or moulding surface may be formed. Where for example two layers ofmaterial are flowed onto the moulding surface 2 (or more layers ifdesired) the moulding surface's relief pattern may extend substantiallyinto some or all of the materials. In this manner, a multi-layer productcan be formed. In one such embodiment, traditionally incompatiblematerials may be formed together, such as TPU and PC.

The material(s) are then held within the bounds of the moulding surfaces2, 3 as the product being formed is conveyed along the endless beltsystem 1. Temperature zone 3 (TZ-3) controls the material(s) within themoulding surfaces 2, 3 for a further period of time and allows thematerial(s) to begin reducing in temperature from the temperature atwhich the material(s) was flowed onto the moulding surfaces.

After a further period of time, the material(s) have reduced intemperature further, and for example may be within the region oftemperature zone four (TZ-4). TZ-4 allows the material(s) to reduce evenfurther in temperature with the glass transition temperatures of thematerial being reached at the end of this zone.

Further temperature zones five, six and seven (TZ-5, TZ-6, TZ-7) areprovided further downstream from TZ-1-TZ-4. These latter zones allow thematerial(s) to reduce in temperature from below the glass transitiontemperature towards an ambient temperature (T_(a)) (for example, downfrom about 90° C. to about 20° C.). These temperature zones are, likethe earlier zones, temperature controlled to allow the material(s) thathave been formed to cool while held within the die or moulding surfaces.The formed product this reduced to below the glass transitiontemperature of the material(s) and to near ambient temperatures (T_(a))for removal from the moulding surface.

The length of time the material(s) need to be held within eachtemperature zone will depend on the linear line speed (LS-1) that theconveyor system 1 is operating at (e.g. meters/min). The length of timewill also depend on the ability to control the rate of cooling of thematerial(s). The period of time within which the material(s) is held ineach temperature zones can be controlled via adjusting the line speedLS-1 of the conveyor or length (i.e. lengthen or shorten) the coolingzones CZ. These periods will also be dependent on the cooling rates ofthe polymers being formed.

Generally, it is considered the heating zones (TZ-1, TZ-2) will beoperated as fast as possible—this minimises the period of time energy isrequired to keep the material(s) above their T_(g). Operating thesetemperature zone segments quickly will help minimise total (energy)heating requirements for the process and for delivering the material orpolymer(s) at their most molten state.

Generally, it is considered the cooling zones (TZ-3, TZ4, TZ-5, TZ-6,TZ-7) will be operated according to the time needed for cooling of thematerial(s) to below their glass transition temperatures and further toambient temperature T_(a). Sufficient heat energy must be removed fromthe material(s) that have been formed such that on removal of thematerial from the die the material holds the formed shape. Removal fromthe die or moulding surface before sufficient heat energy has beenremoved from the material may result in heat energy from within thematerial continuing to transfer to the external surfaces of the materialand product thus formed.

If the product formed is not cooled enough, the core of the product mayretain enough heat energy to transmit to the surface of the formedproduct, resulting in destabilisation of the surface structure andproduct itself. In such a case the structural stability of the productthus formed may be lost as the material has not yet lost sufficient heatenergy to set into a solid phase. As different materials (polymers) maycool at different rates, the CZ may be adjusted accordingly.

In the case of multi-layer products to be formed, the materials to beused (e.g. polymer) are elevated to above their glass transitiontemperatures. A first of the polymers P(a) is then continuously flowedas an extrudate onto the lower moulding surface 2 of an endless beltsystem 1 from an extruder head 6. The second of the polymers P(b) islikewise continuously flowed as an extrudate onto the upper surface 3 aof the first polymer P(a). In this manner, dual layers of polymer arelaid onto a moulding surface 2. This is the first two temperature zonesegments completed. The polymers P(a), P(b) are then conveyed, whilststill above their respective glass transition temperatures, to receiveapplication of the upper moulding surface 3 to at least the upper-mostsurface 3 b of the upper polymer layer P(b). The upper moulding surface3 is brought to bear and apply pressure on the polymers and formation ofthe upper moulding surface is performed. Pressure from the uppermoulding surface 3 assists in holding the polymers in place between themoulding surfaces 2, 3. Such pressure may also be used to compress thepolymers into the surface relief features of the die or moulding surfacebeing used. Pressure is applied at the die pressure point (Dp) asindicated by FIG. 6. The surface relief features determining the patternor three-dimension shape to be formed of the polymers. Examples ofproducts that may be formed are described below.

‘D’ is the width of material flowed onto the lower moulding surface 2.The width of material can be adjusted via the extruder head 6. Width maydepend on the application of product being so formed. The limitingfactor for processing of the extrudate into a formed product will dependon the diameter ‘C’ of the moulding surface 2. Control of the flow fromthe extruder head 6 may also become a problem—flow control nay beassisted by inclusion of a melt pump (not shown). Clearly however,providing greater width belt systems and moulding surfaces will enablegreater width product to be formed.

‘A’ is the angle of flow of material from the extruder head 6 to themoulding surface 2. The angle of the extruder head may be altered toalter the angle of the extrudate onto the die surface. Altering theextrudate angle assists in the flow direction that the extrudate meetsthe die surface. This ability to vary the die angle accommodates slightvariations in extrudate and process speed and a variation of a melt flowindex of a polymer when used in series with another extrudate with adifferent melt flow index from a second extrusion head. The ideal anglefor the extrudate to meet the die surface is between about 60° and about90°. This angle range helps ensure minimal air entrapment between theextrudate and the die surface. Die angles can also be used toaccommodate alignment of several dies within the available area on whichto flow the polymer onto the die surface.

‘R’ is the turn angle at which the material flows onto the lowermoulding surface. A minimal turn radius ensures minimal air entrapmentbetween the extrudate and the die surface. The radius must not be tootight as to cause the flow of the polymer around the radius to impartstress into the polymer. As a general rule the radius should be aminimum about two times the gauge of the extrudate and no greater thanabout ten times the gauge of the extrudate.

‘B’ is the vertical height from the lip of the extruder head 6 to thesurface of the lower moulding surface. The ability to adjust the heightof the top die surface, the bottom die surface and the extruder dierelative to the bottom die surface enables the length of the freefalling extrudate onto the die surface to be controlled. The control ofthis extrudate length minimizes stretch/elongation of the extrudate fromthe gravitational weight of the polymer. Stretch/elongation would impartstress into the polymer, change the gauge of the extrudate and reducethe width of the extrudate.

‘ES-1’ is the linear speed at which extrudate is flowed out of theextruder head 6. The linear speed of the extrudate should be matched tothe line speed of the process/belt as closely as possible. If theextrudate speed line is lower than the speed of the process/belt, theextrudate will be elongated or stretched causing the polymer to bestressed, the gauge of the extrudate decreased and the width of theextrudate reduced—commonly referred to as “neck in” of the extrudate.

If the extrudate speed line is higher than the line speed LS-1 of theprocess/belt, the extrudate will gather, pool, pleat or ripple and causean uneven gauge extrudate on the die surface. For example, ‘LS-1’ is thelinear speed or line speed (meters/minute) at which the endless beltsystem 1 is running.

For an application where a small process direction stretch ororientation of the polymer may be beneficial to the end product a slightincrease of the process speed over the extrudate speed will inducepolymer orientation. This polymer orientation may be used to provideoptical properties or increased strength in the flow direction to theproduct being manufactured.

The linear speed (e.g. meters/minute) of extrudate from the extruderhead 6 ES-1 is advantageously matched to the line speed LS-1 (e.g.meters/minute) of the endless belt system. In this manner, the materialbeing continuously flowed onto the lower moulding surface 2 is notstretched or moved or pulled onto the moulding surface (this would bethe relative difference in linear speeds between ES-1 and LS-2). Thismay facilitate the minimising of stress or tension applied to theextrudate. Instead, the extrudate is allowed to be laid or flowed ontothe moulding surface, the moulding surface accepting the extrudate andthe extrudate flowing into the surface relief features of the mould:

With reference to FIGS. 7-12 (some figures not showing upper mouldingsurface 3), there is shown is an endless belt system 1 comprising alower moulding surface 2 and an upper moulding surface 3 that can begauged and brought into contact with the upper surface 3 a of a polymerP(a) continuously flowed from an extruder head 6 out of an extrusionsystem (details not shown). The polymer P(a) is provided at above itsT_(g) such that on flowing of the polymer to the lower moulding surfacethe polymer assumes the shape of the mould. The process can be runaccording to the various temperature zones as described above.

FIGS. 11 and 12 illustrate a further embodiment of the invention inwhich more than a single extrudate is to be processed. FIG. 11illustrates a single extruder head 6 flowing dual layers P(a) and P(b)of extrudate material onto a lower moulding surface 2. FIG. 12illustrates a pair of extruder heads 6 flowing layers of extrudatematerial P(a) and P(b) onto a lower moulding surface 2. It will beappreciated more than two extruder heads may be employed for additionallayering of extrudate. Alternatively, extruder heads enabled to extrudemultiple layers of material may be used.

FIGS. 13 a, 14 a, 15 a are SEM images of various moulding surfaces, withcorresponding FIGS. 13 b, 14 b, 15 b being their respective formedproducts (i.e. moulded PS).

FIG. 16 illustrates a schematic section through one part of a mouldingsurface. For example, the moulding surface can be the lower mouldingsurface 2. Provided dimensions are an aperture ‘a’ (e.g. about 5micrometers diameter), thickness of aperture t₁ (e.g. about 2micrometers), height from aperture to top of moulding surface t₂ (e.g.about 50 micrometers), internal radius R1 (e.g. about 15 micrometers)and external radius R2 (e.g. about 25 micrometers), and opening ‘b’(e.g. about 50 micrometers).

FIGS. 17-21 illustrate the mould of FIG. 16 so used when material (e.g.polymer) is either flowed onto the mould from surface 2 _(I) or surface2 _(II).

FIG. 17 is an SEM image demonstrating the ability of a low stressmaterial (e.g. liquid polymer) to be flowed through a small aperture (a)from surface 2 _(I) to fill the mould cavity. This figure exemplifiesthe invention's ability to pass a large volume of material through asmall aperture enabling low stress high volume flow of polymer to form ahigh aspect ratio product. The volume of material in the cavity of themould is over fifty times the volume of the material which may be heldin the volume bounded by aperture (a) and thickness t₁.

FIG. 18 is an SEM image of the moulding surface 2 _(II) with aperture(a) shown.

FIG. 19 is an SEM image demonstrating the ability of a low stressmaterial (e.g. liquid polymer) to be flowed from the moulding surface 2_(I) through to the other side 2 _(II) of the mould. Image shows apolymer P(a) flowing out of the aperture (a) at the underside surface of2 _(II).

FIG. 20 is an SEM image of a formed polymer once removed from themoulding surface. The formed polymer product is the result from applyinga polymer to moulding surface 2 _(I), but not flowed or pushed throughto extend out beyond the aperture (a). FIG. 21 is an SEM image ofmultiple of the products of FIG. 20, demonstrating repeatability.

In a further embodiment the method of the invention comprises of formingan item in a manner to include a surface or surfaces with surface detailat a nano or near nano-scale, said method comprising applying by flowingor laying or depositing a formable material onto a surface, and formingthe material.

In another embodiment the method of the invention consists in a methodof forming an item with at least one surface that includes nano-sizedsurface relief, said method comprising introducing onto a surface of afirst platen a layer or layers of precursor material(s) to be formed,said material being in a liquid, or molten or near molten or non rigidstate when introduced, applying a pressure onto the layer(s) by way of asecond platen that is displaced towards said first platen, to at leastin part form the precursor material, wherein one or both platen carry orhave a surface that includes nano-sized surface relief to form thematerial with, at least in part, a negative thereof.

The surface can be a substrate or platen receiving one side of atwo-sided die or an imprinter die or a stamping mould or mouldingsurface. The moulding surface can be a part of a continuous forming tool(CFT), a moving belt former (MBF), an imprinter or a die or a suitableimprinter mould. The die or moulding surface is desirably a materialhaving a relatively high heat transfer rate or high thermalconductivity.

It is recognised the moulding surface may be a platen or a part of anyone of, for example, a moving belt former, a stamp imprinter or a dieimprinter or a stamping mould continuous forming tool.

As illustrated by FIGS. 7-12, an endless belt system can be used inoperating the process of this invention. The method and apparatusdescribed by the contents of PCT/NZ2006/000301 and PCT/NZ2006/000300 arehereby incorporated fully by reference. The method and apparatusdescribed by those applications may be particularly suitable forimplementing the present invention.

Advantageously applying the material in a manner that does not requirethe material (e.g.) polymer to move across the die surface, when thematerial is in a relaxed or a reduced stress condition allows reducedforming pressures for forming desired products. The reduction or nearelimination of required forming pressures aides in minimising materialstresses of deformation and may further reduce material shrinkagestresses when changing from a molten state or a liquid phase to a solidstate or solid phase. For example, this invention enables the forming ofmoulded products having minimal surface stress or tension during theforming process which may be imparted to the product so formed. Theseadvantages appear achievable by the use of materials that are able to bealtered to a flowable state or condition prior to a forming operation.Also, the material has not been required to flow across the die surface.

For example, the material may be at or near a substantially molten statewhen applying to the surface of a forming tool. Alternatively, thematerial may be in or near a substantially liquid phase whencontinuously applying to the surface of a forming tool. Suchcharacteristics allow for the flowable application of the material.

In one embodiment the material may be applied to the surface by flowinguntil a sheet of material substantially covering the surface isachieved.

More particularly, the heat transfer characteristics of the material mayat least in part contribute to the maximum depth of material able to beapplied to the surface for a subsequent forming operation. However, itis anticipated the provision of a temperature controllable cooling zonecan allow production of high heat capacity materials or products ofincreased depth or thickness in allowing the material (polymer) toreduce to below its (or their) glass transition temperatures prior toremoval of the material from the moulding surface.

It particular embodiments, the material can be applied to the surface toa depth of less than about 50, 40, 30, 20, 10 mm, or less than about 5mm, or less than about 3 mm, or less than about 2 mm. Yet further, thematerial is to a depth of 0.1 mm to about 3 mm. Alternatively, the depthis about 4, or 3, or 2 or 1 mm.

In another embodiment, the depth of material applied to the surface canbe to a depth of at least about 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15,20, 25, 30, 35 40, 45, 50 or 55 micrometers or about 56, 60, 65, 70, 75,80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150,155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 220, 240, 260, 280,290, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900,950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500,1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2050, 2100,2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2550, 2600, 2650, 2700,2750, 2800, 2850, 2900, 2950, 3000, 3500, 3550, 3600, 3650, 3700, 3750,3800, 3850, 3900, 4000, 4050, 4100, 4150, 4200, 4250, 4300, 4350, 4400,4450, 4500, 4550, 4600, 4650, 4700, 4750, 4800, 4850, 4900, 4950, 5000micrometers or 0.1 millimeters to about 3 millimeters and useful rangesmay be selected between any of these values (for example, about 0.5millimeters to about 3 millimeters, about 0.2 millimeters to about 2millimeters).

In another embodiment, where the material is polystyrene, itstemperature can be controlled to be about 230° C. on contact with thesurface, and where the material is polycarbonate its temperature can becontrolled to be about 300° C. on contact with the surface. Temperaturecontrol can be achieved by any manner of heat regulatory systems, forexample electrical heaters or heat exchangers. Temperature control ofthe surface or of parts of the forming tools can also be controlled.Again, these may be by temperature regulators such as electrical heatingsystems, infra-red (IR) or other heat exchangers, for example hot oilsystems for heating of platens of a forming tool. It will be understoodthat other methods of heating surfaces or maintaining surfacetemperatures is contemplated and not limited to those systems describedherein only.

It is also contemplated that the material may be temperature controlledaccording to predetermined material rheological characteristics, forexample to control the physical properties of the material such as to amolten or semi-molten or liquid phase depending on its viscosity ormalleability at particular temperatures.

In controlling of the temperature of the material before a formingoperation it may be considered that inputting energy to the material toform a semi-molten, molten or liquid phase of material and allowing thematerial to collect and pool may assist in subsequent flowing or lyingof the material onto the surface. The material can be supplied to thesurface in a semi-molten, molten or liquid phase. Alternatively, thematerial may be supplied to the surface in a sheet form.

Suitable materials may involve one or more of: a molten mouldablematerial, a thermoformable material applied at a thermo-formabletemperature, a thermoformable material to be heated by the surface or aforming tool or tools to a formable condition, a thermoformable materialor molten mouldable material to be cooled by the surface or a formingtool or tools or otherwise, a thermoformable material to be thermoset bythe surface or a forming tool or tools, and any of the foregoingtogether with one or more material of a different character.

It is contemplated the present invention can be used with any flowablematerial, or a plastically deformable material such as for examplepolymers and metals. However, most preferred materials includethermosetting polymers or thermoplastic polymers. Polymeric materialsmay include hydrocarbonaceous materials, including polymeric materialscomprised of plant derived oil materials as recent trends suggest willbecome more widely available.

It is also appreciated those materials for use with the method of thepresent invention should be able to be able to be applied to the surfaceat their thermoformable temperature.

Particularly suitable and contemplated materials include, but are notlimited to the following, polymeric composites, polycarbonates (PC),polystyrenes (PS), general purpose polystyrenes (GPPS) or polymethylmethacrylates (PMMA). Materials that may be particularly suitable foroptical media applications include, but are not limited to thefollowing: ultraviolet stabilised thermoplastic polyurethanes,polycarbonates, polymethyl methacrylates, or general purposepolystyrenes.

Other suitable materials include conductive polymers and polymerssuitable for wound dressings.

Examples of metals metal alloys, pure metals, metallic oxides (such asfor example ceramics that may be sintered as part of a forming processor a subsequent process step to a forming operation), non-crystallineceramics, crystalline ceramics, non-oxide ceramics such as for examplecarbides, borides, nitrides or silicides, or composites of these forexample particle reinforced or combinations of oxide and non-oxideceramics. Where for example metallic oxides are to be used, such asoxides of alumina or zirconia, ceramics are to be formed, the formingstep may provide for forming of a green body or intermediates of a greenbody and a sintered item.

Some further examples of ceramics, optionally provided in a slurry formor on a supporting substrate for subsequent forming operation mayinclude: Barium titanate (often mixed with strontium titanate), Bismuthstrontium calcium copper oxide, Boron nitride, Ferrite (Fe₃O₄), Leadzirconate titanate, Magnesium diboride (MgB₂), Sialons/Silicon AluminiumOxynitrides, Silicon carbide (SiC), Silicon nitride (Si₃N₄), Steatite(magnesium silicates), Titanium Carbide, Uranium oxide (UO₂), Yttriumbarium copper oxide (YBa₂Cu₃O_(7-x)), Zinc oxide (ZnO), Zirconiumdioxide (zirconia).

Suitable materials may desirably meet the flowable characteristicrequirements.

It should be appreciated the skilled person will understand there arenumerous other materials not listed here that will operate effectivelywith the present invention and that the present invention is not limitedto those illustrative examples described herein.

Advantageously the material can be temperature controlled beforeapplying to the surface. Alternatively the material can be temperaturecontrolled when applied to the surface. In yet a further alternativeembodiment the material can be temperature controlled before applying tothe surface and temperature controlled when applied to the surface.Temperature control can be achieved by measuring the temperature of thematerial and adjusting it by heaters. The heaters can be direct heaters,such as an electrical heater immersed in the material, or can anindirect heater(s) such as a heat exchanger imparting heat from a heattransfer fluid through a conductive surface to the material to be heated(e.g. a shell and tube heat exchanger).

It should also be appreciated the surface or surfaces of the formingdevice (MBF, CFT, die or mould) can be heated to maintain temperature ofthe material to be formed or being formed. Provision of a heated surfacemay also assist in slowing the cooling or annealing of the material orrate of freezing of the material to below the T_(g) of the materialbeing processed before, during or after a forming operation.

The surface used for the forming operation can be configured or arrangedaccording to predetermined products to be formed. The imprinting orforming surface can be formed of metal coated nanotubes arranged orconfigured as desired, although other surface mould methods are alsocontemplated for us in this invention.

Advantages of using a continuous forming tool (CFT) such as thatdescribed in the PCT applications referenced above may include one ormore of: the ability to vary the pressure in the forming zone, lateraland axial expansion of forming blocks, raising and lowering of bottomtrack/platen with moulding surface, ability to vary clamping pressure ofthe machine between runs and over the length of track.

CFT manufacturing technology can be used for flat sheet and many otherprofiles, for example, three-dimension shapes, asymmetric forms and isnot limited to axially symmetric forms (for example pipes) or opticallenses. Further advantages of this manufacturing technology include:accommodating of intermediate processes, such as injection moulding,part insertion, top and bottom tracks/platens can differ in length andspeed, high degree of accuracy alignment of mating dies, ability tocontrol temperature of each forming block and/or each track separately,high forming speeds, forming block side plates take load, not faces andedges of forming blocks, can work with molten and semi-moltenmaterial(s), liquid or semi-liquid material(s) flow form to bottom dieand then are pressure formed, very small shapes can be imprinted, atleast down to or even below 1 nanometer in width or depth, and thecapability of having non-linear pressure forming zones.

The present invention advantageously provides for the flowing or lyingof a polymer continuously on to a die or moulding surface in a way thatthe polymer does not flow across the die or moulding surface. The die ormoulding surface is controlled or allowed to be at or close to thetemperature of the polymer, the polymer being at or close to its liquidphase. The polymer is applied and held on the die or moulding surface ina manner such that the polymer is not moved across the die or mouldingsurface, the polymer moving due to gravity but not any other forces. Thepolymer is held in its form in the mould for a sufficient time until acompression moulding force is applied.

Desirably, the process of the invention is designed to impart minimalstress into the polymer during forming. This is because the polymer isprovided to the die or moulding surface when in a relaxed state,preferably its most relaxed state possible (i.e. liquid phase) and theamount of movement of the polymer is minimalised by only taking up thesurface pattern of the die or moulding surface. This is possible as thepolymer is as close to its liquid phase as possible and is laid directlyfully across/onto the die or moulding surface. The polymer need not bemoved significantly across the mould surface to form the surface patternor relief. Instead, the upper die or moulding surface is used to applyminimal pressure, for example in the range of 1-3 kg/cm2, to finish ormove the polymer into the form of the surface pattern or relief of themoulding surface.

According to the invention, the forming zone can be an extension of theheating zone. The cooling zone is only initiated or begins once thepolymer to be formed has been “shaped”. In comparison to existingprocesses, normally the cooling zone is provided immediately on exit orafter exiting the extruder or injection moulder.

Further, the process of this invention is able to transfer a liquidphase polymer into a compression zone at sufficient speed and tomaintain the polymer in its liquid phase without significant movement ofthe polymer across the die or moulding surface,

The process imparts almost no stress in the polymer during forming—thisis due to the polymer being in liquid phase, totally relaxed, minimalmovement of the polymer across the die surface, the temperature of thedie surface during forming being close to the polymer temperature, acontrolled cooling cycle and the high speed of the forming process. Thepolymer is not injected or subjected to high forces/pressures or largeflow paths.

Low stress also results in the ability to remove the die from thepolymer whilst the polymers temperature is still relatively high andduring final cooling the shape is not distorted. This is because thereis little or no internal stress in the material formed.

Products produced have lower chance of distortion in use—particularly inelevated temperature and/or exposure to chemicals—causing relaxation ofany internal polymer stress, such as shear stress or formingstresses—which otherwise cause distortion of patterns formed.

Low stress also results in the ability to form flexible materials (e.g.TPU) with high compressibility into micron and sub micron patterns—thesepatterns a normally lost when released from a mould which has appliedcompressive force to form the patterns.

The use of a highly thermally conductive die or moulding surface enablesthe die surface to rapidly take up or be increased or adjusted to thepolymer's temperature on application to the die surface. Likewise, sucha die or moulding surface is then able to allow cooling or heat transferaway from the polymer when in contact with the die surface.

Advantageously, this invention enables the forming the polymer withpressure from about 1 kg/cm² to about 3 kg/cm², although as previouslydescribed other pressures or pressure ranges may be used in the process.These particular forming pressures are relatively very low compared toknown forming techniques. Known techniques for injection moulding areoften in the region of about 260-350 kg/cm².

As described previously, the ability to form multiple polymers on themoulding surface is enabled with this invention, for example the formingof two polymers simultaneously is possible. Able to pattern both sidesof a product at the same time and align the patterns or mouldingsurfaces to produce a desired formed product. The alignment of patternson either side of the extrusion is achieved through the alignment thedie surfaces. Alignment can be controlled either through physicalalignment of the surfaces by using taper interference or other commonphysical methods or by controlling the location and relative speeds ofthe die surfaces through sensor feedback from the die surfaces.

Aligning the patterns on either side of a product may be used to enhancethe optical properties of the product.

Able to form multi layer laminations of different polymers and applydifferent patterns to the two outer surfaces which may be differentpolymers—one polymer/surface could provide UV stability and havepatterns providing a non-reflective surface and the otherpolymer/surface could provide chemical resistance with an increasedsurface area for applying an active coating—e.g. an electrode.

The forming of high aspect ratio products is possible due to the minimalpolymer flow across the moulding surface and the die surface temperaturewhich allows the polymer to flow into the surface pattern or reliefcavities of the die or moulding surface under the polymer's own weightwith minimal additional compressive moulding force (low stress)required. Aspect ratio's of about 10:1 or even up to 20:1 or evengreater are achievable (depth: width of surface relief).

The invention further provides for a process which can vary heatingzones HZ and cooling zones CZ time and length, the extruder die height,the speed differential between the extrusion melt from the extruder diehead and the process speed to control extrusion gauge and width,including speed control to vary the radius of the extrusion melt appliedonto the die or moulding surface.

Production rates of formed product at linear line speeds of around 36meters/minute (or greater) are achievable. Existing forming techniques,for example of nano-scale relief formed structures, is significantlyless than this (existing techniques for production rates of nano-scaleforms structures are in the region of about several square meters perday). In contrast, the present invention may readily achieve productionof around 25,000 m² per day (at operational conditions of a 36 m/minuteon a 500 mm wide moulding surface operated for 23 hours per day).

Further advantages include the ability to reduce and/or tune and/orcontrol the gauge of the extrusion by speeding up the draw-off ratethrough a speed differential between the extrusion speed ES-1 and thedie surface speed or line speed LS-2.

Adjusting the variables in relation to process speed, length of heatingtime, length of cooling time, width of process and productivity can allbe used to produce desired products. A limiting factor in operation ofthe invention is currently understood to be extrusion speed, althoughthis may be increased as control of extrudate flow is improved.

This invention is considered appropriate for those materials, such aspolymers, capable of extrusion, including processing of a wide range ofpolymer viscosities, from about 1 MFI to about 50 (or even greater) MFI(MFI being the ‘melt flow index’). Typically this is not possible withother techniques, such as in extrusion, hot embossing or injectionmoulding.

Extrusion gauges from about 10 (or less) micrometers to about 20 mm arecontemplated, including the patterning of large surface areas, such asfor example about 3 m in width or may be wider than this depending onthe necessary application or machine or moulding surface to be used. Inaddition the present invention is enabled for the patterning across thetotal width D of an extrudate. In comparison, other production processesare usually only capable of producing up to about 8″ (inch) widthproducts (e.g. wafers).

A continuous process, both a continuous feed of polymer in to theprocess and a continuous product production, is possible with no joinsin the pattern or surface relief pattern being so formed.

Further, the product being formed can be moulded by the mouldingsurfaces around three-dimensional surfaces, not just flat or planarsurfaces.

The present invention further contributes to the ability to combinenormally non-compatible materials due to their different processingrequirements (e.g. glass transition temperatures or MFI or melt flowviscosity at once). Examples of these include multi-layer formedproducts of polycarbonate (PC) with thermoplastic polyurethane (TPU).

It is considered that a majority of the forming of the product to beformed occurs by the liquid polymer assuming the surface relief orpattern of the moulding surface when initially flowed onto the surface,gravity assisting in moving the liquid polymer into the mould before anysubsequent mechanical force is applied by the compression step of theupper moulding surface.

The present invention avoids other problems in the prior art, such as“roll-stack chatter” which is apparent under normal extrusion roll stackprocessing. “Chatter” occurs due to differential speed between the rollstack's rollers during the forming due to pressure, motor dive controland friction influences.

Ability to vary temperature zones—cooling/heating—re-heating andre-cooling (annealing), very small differential temperatures betweenpolymer and die surface, very large differential temperatures, verygradual decrease in a particular zone (e.g. forming zone and firstcooling zone until below glass transition temperature

Ability to vary temperature onto top or bottom surface of extrusion—mayrequire different temperatures for either different polymers ordifferent patterns—could also be utilized to provide uniform orun-uniform “crystallization” of polymer (particularly useful withoptical substrates or for cross linking polymer on one surface—e.g.crystalline polyethylene terephthalate (CPET)).

Able to bring together two polymers which will not adhere to eachother—form holes through the first layer and partially into the secondlayer with the die surface (pins shapes for example), once removed fromthe process and the die surface the two layers are delaminated(separated) leaving one layer with holes completely through. An exampleof the materials could be thermoplastic polyurethane (TPU) as a firstlayer and polypropylene (PP) as a second layer.

In a suitable endless belt system or other apparatus for operating thepresent invention there would be the ability to vary the extrusion dieheight (B) and angle (A).

The method according to the present invention can facilitate the formingof one or more of the following types of items: membranes for separationsuch as for separation of components from or within water, chemicals,gases, blood, or use within fuel cells, sensor devices, light diffusers,light emitters, wave reflecting or absorbing such as radar etc,electronic circuits or circuitry, particle alignment or aligningtechnologies, water repellents or water repelling technologies such ashydrophobic materials, optical media such as a liquid crystal display(“LCD”) or a compact disc (“CD”) or a digital video disc (“DVD”)technology or a photo-voltaic cell, memory storage devices, medicaldevices such as for skin repair or wound repair (e.g. bandages), drugdelivery mechanisms or devices, reduced (low) friction surfacematerials, increased (high) friction surface materials, laminationtechnology, radio frequency identification (“RFID”) chips, conductivepolymer layers/ products/ circuits, light bending technologies such asnegative light reflections. Particularly preferred items may includeforming of or precursors for optical media such as photovoltaic cells,compact discs (CD), digital video discs (DVD), liquid crystal displays(“LCD”) or elements of conductive circuits or circuitry, includingnon-reflective or anti-reflective patterns or films for subsequentmetalising and removal of the formed material to leave a metal negativeimage of the formed material (for example the formed product can be usedto for the base for a subsequent metallisation treatment).

It will be appreciated by the skilled artisan that there may be otheritems that may be manufactured according to the present invention thatare not specifically listed above.

In another embodiment of the present invention the items above can beformed from a material precursor that is laid or applied onto one platenof a press to be formed in conjunction with at least one other platenpressed toward one another, wherein the items may be subsequentlyformed. Such items can be formed where the present invention forms apart of an overall manufacturing process or is an intermediate part of amanufacturing process or which provides for a material or precursor formanufacturing of an item. It will be understood by the skilled artisanthat the present invention may find application as part of othermanufacturing processes or procedures.

EXAMPLE 1

Polystyrene is:

-   -   (i) heated and maintained at a temperature of 230° C.,    -   (ii) the heated polystyrene is transferred and applied to a        surface of a continuous forming tool, such as the surface        labelled 26 or 24 of PCT/NZ2006/000300 and formed according to        the method of PCT/NZ2006/000301,    -   (iii) a pressure of between about 1 kg/cm² to about 3 kg/cm² is        applied to the material on the surface,    -   (iv) pressure is released by separation of the forming surfaces,        thereby releasing the item or product thus formed.

The product thus formed is that shown in FIG. 1 with product analysisshown in FIG. 2 and an atomic force microscope image of a part of theproduct shown in FIG. 3.

EXAMPLE 2

Polycarbonate is:

-   -   (i) heated and maintained at a temperature of 300° C.,    -   (ii) the heated polycarbonate is transferred and applied to a        surface of a continuous forming tool, such as the surface        labelled 26 or 24 of PCT/NZ2006/000300 and formed according to        the method of PCT/NZ2006/000301,

(iii) a pressure of between about 1 kg/cm² to about 3 kg/cm² is appliedto the material on the surface,

-   -   (iv) pressure is released by separation of the forming surfaces,        thereby releasing the item or product thus formed.

The product thus formed is that shown in FIG. 4 with product analysisshown in FIG. 5.

EXAMPLE 3

Polymethyl methacrylate (PMMA) is:

-   -   (i) heated and maintained at a temperature of between 190-240°        C.,    -   (ii) the heated PMMA is extruded from an extruder head and        flowed in a continuous flow on to the lower moulding surface at        a depth or thickness of 1 mm of a moving belt former (MBF) or an        endless belt or a continuous forming tool (such as the surface        labelled 26 or 24 of PCT/NZ2006/000300 and formed according to        the method of PCT/NZ2006/000301), the PMMA is held on the        moulding surface and retained or allowed to remain above its        glass transition temperature (T_(g) PMMA ˜105° C.),    -   (iii) the upper moulding surface is applied to the upper surface        of the PMMA held on the lower moulding surface, the upper        moulding surface exerting a pressure of between about 1 kg/cm²        to about 3 kg/cm² to the PMMA material,    -   (iv) pressure is released by separation of the forming (or lower        and upper moulding) surfaces, thereby releasing the item or        product thus formed.

The table below provides further details of the processing parameters ofthis example. It should be appreciated this example may be appliedacross a wide range of materials to be formed according to thisinvention. Aside from using alternative materials having differentphysical properties, the other processing parameters may be altereddepending on the material to be processed.

TABLE 1 PMMA processing parameters Melt Flow Index (MFI) Avg. MeltExtrusion Glass Flow, g/10 melt transition min @ 230° C. temp.temperature Thickness of Material & 3.8 kg (° C.) (° C.) extrusion (mm)PMMA 1-3 190-240 105 1 Extrusion Extrusion Head Extrusion ExtrusionSurface Die Angle - A Height - B Radius - R width - D width - C (mm)(degrees) (mm) (mm) (mm) [mould surface] 60°-90° 10-50 5 500-505 500Extrusion Speed - 1 Line Speed - 2 (metres/minute) (metres/minute) 10 10

TABLE 2 PMMA temperature variation across process TemperatureTemperature Temperature Temperature Temperature Temperature TemperatureZone 1, Zone 2, Zone 3, Zone 4, Zone 5, Zone 6, Zone 7, Material TZ-1 (°C.) TZ-2 (° C.) TZ-3 (° C.) TZ-4 (° C.) TZ-5 (° C.) TZ-6 (° C.) TZ-7 (°C.) Polymethyl 190-240 190-240 140-180 90-120 70-90 50-70 20-50methacrylate (PMMA)

With reference to FIG. 6, table 2 above provides details of theapproximate temperature profile of PMMA material being processed as itis processed according to this invention. Temperature zones TZ-1, TZ-2,TZ-3, TZ-4, TZ-5, TZ-6, TZ-7 correspond to the various zones of theprocess illustrated by FIG. 6. FIG. 6 provides graphical representationof the temperature profile of a material as it passes through theprocess of the invention.

EXAMPLE 4

Polystyrene (PS) is:

-   -   (i) heated and maintained at a temperature of about 230° C.,    -   (ii) the heated PS is extruded from an extruder head and flowed        in a continuous flow on to the lower moulding surface at a depth        or thickness of 1 mm of a moving belt former (MBF) or an endless        belt or a continuous forming tool (such as the surface labelled        26 or 24 of PCT/NZ2006/000300 and formed according to the method        of PCT/NZ2006/000301), the PS is held on the moulding surface        and retained or allowed to remain above its glass transition        temperature (T_(g) PS ˜100° C.),    -   (iii) the upper moulding surface is applied to the upper surface        of the PS held on the lower moulding surface, the upper moulding        surface exerting a pressure of between about 1 kg/cm² to about 3        kg/cm² to the PS material,    -   (iv) pressure is released by separation of the forming (or lower        and upper moulding) surfaces, thereby releasing the item or        product thus formed.

TABLE 3 PS processing parameters Extrusion Glass Melt Flow melttransition Index (MFI) temp. temperature Thickness of Material (ISO1133) (° C.) (° C.) extrusion (mm) Polystyrene 1-3 230 100 1 (PS)Extrusion Extrusion Head Extrusion Extrusion Surface Die Angle - AHeight - B Radius - R width - D width - C (mm) (degrees) (mm) (mm) (mm)[mould surface] 60°-90° 10-50 5 500-505 500 Extrusion Speed - 1 LineSpeed - 2 (metres/minute) (metres/minute) 10 10

TABLE 4 PS temperature variation across process Temperature TemperatureTemperature Temperature Temperature Temperature Temperature Zone 1, Zone2, Zone 3, Zone 4, Zone 5, Zone 6, Zone 7, Material TZ-1 (° C.) TZ-2 (°C.) TZ-3 (° C.) TZ-4 (° C.) TZ-5 (° C.) TZ-6 (° C.) TZ-7 (° C.)Polystyrene 210-230 210-230 160-180 120-140 80-100 40-60 10-30 (PS)The foregoing description of the invention includes preferred formsthereof.

Modifications may be made thereto without departing from the scope ofthe invention.

The invention claimed is:
 1. An apparatus for continuously forming apolymer comprising: an extruder, including an extruder head, forcontinuously extruding a polymer extrudate, a forming zone adapted toreceive said polymer extrudate above its glass transition temperature,said forming zone defined by a serially advancing first moulding surfaceof a first mould and a serially advancing second moulding surface of asecond mould; a plurality of heat sinks provided on at least one of thefirst moulding surface and the second moulding surface, the plurality ofheat sinks being spaced relative to each other along the forming zone;and a controller configured to actively control the temperature of eachof the plurality of heat sinks; wherein the extruder is configured tocontinuously deposit said polymer extrudate at a linear speed onto thefirst moulding surface prior to the polymer extrudate advancing intosaid forming zone, wherein the first moulding surface is configured tocarry said polymer extrudate into said forming zone, the polymerextrudate being in a substantially liquid phase when being continuouslydeposited onto the first moulding surface, wherein a speed of theserially advancing first moulding surface is configured to substantiallymatch the linear speed of the deposited polymer extrudate, so that onlygravity moves the deposited polymer extrudate into the first mouldingsurface before application of any mechanical force by the secondmoulding surface; wherein the controller is configured to activelycontrol heat removal from the polymer extrudate when the polymerextrudate is in said forming zone by actively controlling thetemperature of each of the plurality of heat sinks to progressivelyremove heat from the polymer extrudate via at least one of the firstmoulding surface and the second moulding surface, transitioning thepolymer extrudate from above the glass transition temperature to belowthe glass transition temperature within said forming zone; and whereinat least one of the plurality of heat sinks is positioned at a moreadvanced orientation through said forming zone and is activelycontrolled to a lower temperature than an adjacent of the plurality ofheat sinks at a less advanced orientation through said forming zone inorder to progressively reduce the temperature of the polymer extrudateas it advances through said forming zone.
 2. An apparatus as claimed inclaim 1 wherein said heat removal occurs via at least one of said firstand second moulding surfaces by at least one of the plurality of heatsinks.
 3. An apparatus as claimed in claim 1 wherein the plurality ofheat sinks are provided for at least one of said first and secondmoulding surfaces, said heat sinks spaced relative to each other in theforming zone in an advanced orientation and a retarded orientationrelative to each other.
 4. An apparatus as claimed in claim 1 wherein atleast one of said first and second moulding surfaces include anano-sized surface texture that can form a substantially correspondingnano-sized surface texture of said polymer.
 5. An apparatus as claimedin claim 1 wherein said first and second moulding surfaces include aplurality of discreet and/or sequentially advanced first and secondmoulding surfaces provided for advancement through said forming zone,each advancing through said forming zone in a paired relationship at asynchronised speed.
 6. An apparatus as claimed in claim 1 wherein atleast one of said first and second forming surfaces is continuous inform.
 7. An apparatus as claimed in claim 1, wherein said first mouldingsurface is presented to receive said polymer extrudate by depositingsaid polymer onto said first moulding surface in a manner that reduces,eliminates or minimises shear stress or other stress in said polymer sodeposited.
 8. An apparatus as claimed in claim 1, wherein said mouldforming to which said forming zone is configured to subject said polymerextrudate to imparts a nano-scale sized surface texture onto at leastpart of a surface of said polymer.
 9. An apparatus as claimed in claim1, wherein said heat removal to which said forming zone is configured tosubject said polymer extrudate to is active.
 10. An apparatus as claimedin claim 1 wherein the extruder head is adjustable in a single plane toalter the angle of the extruder head and the deposited polymer extrudaterelative to the first moulding surface.
 11. An apparatus as claimed inclaim 10 wherein the extruder head is adjustable in a second plane toalter the height of the extruder head relative to the first mouldingsurface.
 12. An apparatus as claimed in claim 1, further comprising oneor more heaters configured to maintain the temperature of said polymerextrudate above its glass transition temperature when entering saidforming zone by heating the first moulding surface to a sufficientlyhigh temperature above the glass transition temperature prior to thefirst moulding surface entering said forming zone.
 13. An apparatus asclaimed in claim 12, wherein the first mould has a leading portion thatextends beyond a leading end of the second mould, so that the leadingportion of the first mould directly receives from the extruder head thepolymer extrudate onto the first moulding surface, and at least one ofthe one or more heaters heats the polymer extrudate to the sufficientlyhigh temperature above the glass transition temperature prior toengaging the second moulding surface at the forming zone.